| Rank |
Pathway / Axis |
AD / Neurodegeneration Context |
Normal Brain Context |
TSF |
Primary Effect |
Notes / Interpretation |
| 1 |
Pyruvate dehydrogenase (PDH) activity |
PDH activity ↓ in AD; thiamine restores PDH flux |
Glucose oxidation support |
R, G |
Mitochondrial energy restoration |
PDH links glycolysis to TCA cycle; impairment contributes to cerebral hypometabolism in AD. |
| 2 |
α-Ketoglutarate dehydrogenase (α-KGDH) |
α-KGDH ↓ in AD brain tissue |
TCA cycle support |
R, G |
Mitochondrial stabilization |
Enzyme reduction correlates with oxidative stress and neuronal vulnerability. |
| 3 |
Transketolase / Pentose Phosphate Pathway (PPP) |
NADPH production ↑; oxidative stress ↓ |
Redox buffering |
R, G |
Antioxidant support |
Transketolase requires thiamine; PPP supports glutathione regeneration. |
| 4 |
Mitochondrial bioenergetics |
ATP production ↑; mitochondrial efficiency ↑ |
Energy metabolism normalization |
R |
Bioenergetic restoration |
Addresses cerebral glucose hypometabolism seen in AD imaging studies. |
| 5 |
Oxidative stress reduction |
ROS ↓; lipid peroxidation ↓ (reported) |
Redox balance support |
R, G |
Antioxidant effect (indirect) |
Improved mitochondrial function reduces ROS generation. |
| 6 |
Advanced glycation end products (AGEs) |
AGE formation ↓ (reported with benfotiamine) |
Glycation moderation |
G |
Metabolic toxicity reduction |
Benfotiamine may reduce glycation-linked neuronal damage. |
| 7 |
Neuroinflammation |
Inflammatory markers ↓ (model-dependent) |
Inflammation moderation |
R, G |
Secondary anti-inflammatory effect |
Likely indirect via improved metabolic and redox function. |
| 8 |
Amyloid / tau pathology |
Indirect modulation reported in models |
↔ |
G |
Disease-modifying potential (uncertain) |
No strong direct anti-amyloid mechanism; effects appear metabolic. |
| 9 |
Clinical cognition outcomes |
Mixed results; some benefit with benfotiamine |
Safe at standard doses |
G |
Adjunctive support |
High-dose or derivative forms may show more promise than standard thiamine. |
| 10 |
Bioavailability / derivative consideration |
Benfotiamine & lipid-soluble forms ↑ CNS penetration |
Well tolerated |
— |
Translation constraint |
Standard thiamine has limited brain penetration; benfotiamine shows improved pharmacokinetics. |
| Feature |
Thiamine (Vitamin B1) |
Benfotiamine |
| Chemical form |
Water-soluble vitamin (thiamine hydrochloride or mononitrate) |
Lipid-soluble S-acyl thiamine derivative |
| Absorption mechanism |
Active transport (THTR-1/2) in small intestine |
Passive diffusion (lipophilic); higher bioavailability |
| Plasma thiamine levels |
Moderate increase with supplementation |
Significantly higher plasma thiamine after oral dosing |
| Brain penetration |
Limited; regulated transport |
Indirectly increases brain thiamine via systemic elevation; better tissue distribution |
| Activation |
Converted to thiamine pyrophosphate (TPP) intracellularly |
Converted to thiamine → TPP intracellularly |
| PDH / α-KGDH support |
Restores enzyme activity in deficiency |
Stronger elevation of transketolase & TPP-dependent activity (reported) |
| Pentose phosphate pathway (PPP) |
Supports transketolase → NADPH production |
More pronounced activation of transketolase reported |
| AGE reduction |
Limited direct evidence |
Strong evidence for reducing advanced glycation end products (AGEs) |
| Oxidative stress impact |
Indirect ROS reduction via improved metabolism |
Stronger reduction of glycation-related oxidative stress |
| AD clinical evidence |
Mixed, limited benefit in trials |
Small trials suggest potential cognitive stabilization |
| Dose ranges studied (AD/metabolic) |
100–300 mg/day (varies) |
150–600 mg/day commonly studied |
| Safety profile |
Very safe; excess excreted in urine |
Generally safe; mild GI symptoms possible |
| Primary AD positioning |
Correct deficiency; metabolic support |
Enhanced metabolic + anti-glycation support |
| Best-fit scenario |
Thiamine deficiency; mild metabolic impairment |
Glucose dysregulation; high AGE burden; metabolic AD phenotype |